Devices of the above type are not new per se. A typical example of a prior art device is that shown in Italian Patent Application No. 67,650A 87. This disclosure relates to wheels for motor vehicles and shows a bearing including a seal between the inner and outer rings which prevents the intrusion of foreign matter such as dirt and water. The seal comprises an outer sealing part secured by way of a sheet metal support sleeve to the outer ring and an inner sealing section attached by a sheet metal part to the inner ring. An elastic sealing element secured by vulcanization runs on a corresponding sealing surface of the sheet metal part. Additionally, the seal incorporates a pulse generator which transmits a plurality of electrical pulses for each revolution of the wheel which are the pulses required by the anti-locking systems for the brakes. The system described forms an advantageous combination of a seal and a pulse generator. The pulse generator can be mounted on either the outer ring or the inner ring depending on the application in question and which of the two rings rotates. For example, the pulse generator must be mounted on the stationary ring since the connecting lines do not permit it to rotate.
In general, it can be anticipated that the stationary bearing ring of a roller bearing will, during operation of the bearing, rotate to some degree by reason of the torque acting on it via the rolling elements. A defective fit or a change in the seating conditions of the stationary ring after prolonged periods of operation will result in the stationary ring wandering on its seating surface. As a result of this unintended rotational movement of the so-called stationary ring, the connecting lines of the known device would be severed since the sealing part in question is rigidly connected to the bearing ring and is thus rotated in the same direction. Severing of these lines of course renders the functioning of the anti-locking system inoperative.